Crystal and molecular structures of two crystallographic modifications of trans-di-iodobis(dimethylphenylphosphine)palladium(II)

Abstract

X-Ray diffraction studies of the crystal structures of two forms of trans-di-iodobis(dimethylphenylphosphine) palladium(II) are summarised. Form I, crystallising as red needles, is orthorhombic with a= 8·79, b= 13·06, c= 17·82 Å; space group P2₁2₁2₁. Palladium atoms are bridged by iodine atoms and two quite short intramolecular palladium–hydrogen interactions follow from the positioning of the phenyl rings on the phosphine ligands. Form II, crystallising as yellow plates, is monoclinic with a= 10·20, b= 10·71, c= 10·23 Å, β= 111·7°; space group P2₁/c. With two molecules in the unit cell, the complex is required to have precise C_i symmetry and octahedral co-ordination of the palladium is now achieved through intermolecular interactions with hydrogen atoms on the β-carbon atoms of the phenyl rings of the phosphine ligands.